Inboard-outboard stern drive



Oct l, 1968 J. w. WARBURTON INBOARD-OUTBOARD". STERN DRIVEv` 4 Sheets-Sheet 2 Filed Jan. 25, 1965 INVENTOR /0h W Mlm/burin,

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Uct. l, 1968 J. W. WARBURTON INBOARD OUTBOARD STERN DRI VE 4 Sheets-Sheet 3 Filed Jan. 25, 1965 w .mi

OC- l, 1968 1. w. WARBURTON 3,403,655v

INBOARD-OUTBOARD STERN DRIVE Filed Jan. 25, 1965 4 Sheets-Sheet 4 INVENTOR.

United States Patent O 3,403,655 INBOA'RD-OUTBOARD STERN DRIVE John .W. Warburton, Bothell, Wash., assignorto Stern- Drive Corporation, Kirkland, Wash., a corporation of Washington Filed Jan. 25, 1965, Ser. No. 427,856

` 1 Claim. (Cl. 11S-41) This invention -is for a marine propulsion unit comprising an inboard-outboard drive which may be attached directly to the stern of a boat.

VIn a boat having an inboard engine or an inboard power plant the most common method for driving a propeller shaft and a propeller is to have the output shaft on the inboard engine connect with a gear box. Then, the output shaft of the gear box connects with a shaft which in turn may connect with an intermediate shaft and the intermediate shaft connects with the propeller shaft or the output shaft from the gear box may connect directly with the propeller shaft. Also, with the conventional inboard engine there is a separate rudder and steering system for the boat. With my invention it is possible to combine the rudder `and steering system with the means for driving the propeller and propeller shaft.

The inboard-outboard stern drive of this invention is a marine propulsion unit that is attached directly-to the stern of the boat. This unit is the rudder system for steerage and contains a mounting shaft or the propeller shaft for the propeller and the power input shaft which is coupled to the inboard type marine engine. The marine engines power is transmitted to the mounting shaft forthe propeller. The method used in this inboard-outboard stern drive is unique in that all interconnecting shafting and gearing, which necessitates critical alignment o f these parts, is eliminated. In place of this there may be employed a gear pulley -and a at tooth type belt or a gear belt, or a gear and a chain. The steering action of this stern drive unit is obtained by moving the entire drive unit about the vertical pins of the steering ring or the gimbal ring. The steering ring is held in position by the horizontal pins of the mounting unit which fasten directly to the boats transom. An-adjustable'ball shaft or support screw extends from the transom housing or transom mounting unit with the ball end supporting the drive unit. By adjusting the ball shaft the drive unit may be positioned to improve the boats trim for best performance. In the event the drive unit strikes an obstruction while under way, the drive unit can pivot aft about the horizont-al pins of the steering ring or the -gimbal ring. The drive unit may be also pivoted aft manually for moorage or towing purposes. An automotive type drive shaft connects the engine power to the mounting units output shaft. A universal joint connects the mounting units output shaft with the drive units input shaft. The universal yjoint connecting the mounting units output shaft and drive units input shaft is located inside the steering ring or the gimbal ring so as to Iallow the drive unit to pivot for both steering and tilting. The mounting units output shaft, the drive units input shaft, and the drive units propeller shaft are supported by ball bearings. The drive units input shaft connecting with the propeller shaft belt is designed to operate dry, therefore no lubrication of any type is required. The mounting unit and the drive unit are sealed water tight.

An object of this invention is the provision of a port-able, light-in-weight stern drive unit; a stern drive unit which eliminates many expensive parts of the conventional drive for an inboard engine; a stern drive unit which eliminates costly and time consuming mechanical alignment of the drive for an inboard engine; and, a stern drive unit which is inexpensive to manufacture and to maintain as com- ICC pared' to the drive units for conventional inboard engine equipment.

These and other important objects and advantages of the invention will be more particularly brought forth upon reference'to the accompanying drawings, the following detailed specication of the invention, and the appended claim. 1

In the drawings:

FIGURE 1 is a fragmentary vertical longitudinal cross-sectional view of a specific embodiment of the invention constructed in accordance with the preferred teachings thereof;

FIG. 2 is an elevational view of the rear of the stern drive and showin-g the propeller as being partially hidden;

FIG. 3 is a plan view looking down on the stern drive as'mounted on the transom of a boat;

FIG. 4 is a side elevational View of a boat with that portion of the side near the stern of the boat broken away to show the engine, and the means for connecting the output shaft of the engine with the stern drive;

FIG. 5, taken on line 5-5 of FIG. 1, illustrates the gear pulleys and the gear belt connecting the gear pulleys;

FIG. 6 illustrates gears or sprockets and a chain connecting these gears or sprockets for driving the propeller FIG. 7 illustrates the chain connecting the gears 0r sprockets of FIG. 6; and

FIG. 8 is a plan view looking at the steering mechanism for the stern drive and illustrates a steering rod connecting with a steering ring or a gimbal ring.

With reference to the drawings it is seen that the invention comprises a stern drive 10 having a transom housing or mounting unit 12 and a drive unit 14. The transom housing or mounting unit 12 is mounted on a transom 16.

The transom housing or mounting unit 12 has a generally circular base 18 which has two outwardly directed spaced apart mounts 20. The mounts 20 project away from the base 18 at substantially right angles or are substantially perpendicular to the base 18. On the other side of the base 18 there is an integral cylindrical tube 22. The tube 22 is hollow and aligns with a passageway in the base 118. The lower end of the base 18 depends into a plate Imember 24. In the lower end of the plate member 24 there is a capped passageway 26. In the upper mount 20 there is a drilled passageway 28 and in the lower mount 20 there is a drilled passageway 28. Positioned in these two passageways 28 are gimbal studs 30 of the gimbal ring 32. Also, in the passageways 28 are bronzed brushings 34. It is seen that the gimbal ring 32 can rotate horizontally around the two gimbal studs 30, which are sub- -stantially vertical, depending upon the position of the boat in the water.

The gimbal ring 32 also has horizontally directed studs 36. The drive unit 14 comprises two rear upper spaced apart mounts `40. In back of these mounts 40 there is an upper housing V42 and descending from the upper housing 42 there is a descending casing 44. In the lower part of the descending casing 44 there is a lower housing 46. In FIGURE l it is seen that the descending casing comprises substantially a shell having a hollow interior. In each of the mounts 40 there is a passageway 48 for receiving the gimbal studs 36. As is easily seen, the drive unit 14 may rotate vertically around the gimbal studs 36.

In the upper housing 42 there is a cavity 50. In this cavity 50 there are two spaced apart ball bearing races 52. There is a shaft 54 positioned in these two ball bearing races 52. On the outer end of the shaft 54 there is a retainer ring 56 and in the inner end of the shaft 54 there is a retainer ring 58. Surrounding the inner end of the shaft 54 is a seal 60. The inner end of the shaft 54,

i.e., that end near the transom 16, connects with a universal joint 62. As is seen in FIGURE l the universal joint is substantially inside of the gimbal ring 32. The universal joint 62 connects with the transom shaft `64 which passes through the transom 16 of the boat and is positioned inside of the member 22. In the member 22 are two spaced apart ball bearing races 66. As is seen in FIGURE l, the threaded member 22 projects through an opening 68 in the transom 16. A nut 70 is threaded over the member 22 and tight against the transom 16 so that the transom 16 is between the member 18 and the nut 17 to firmly position the stern drive 10 on the transom of the boat. In the member 22 and bearing against the races 66 are seals 72. These seals position the races 66.

The universal joint 62 is enclosed in a universal-j0int boot 74 so as to give protection to the universal joint against moisture and salt water.

From this discussion it is seen that with the universal joint 62 mounted inside the gimbal ring 32 that if the drive unit 14 s rotated horizontally around the gimbal studs 30, that the shaft 54 will also be able to move the drive unit 14 in a horizontal direction. Also, if the drive unit 14 is rotated vertically around the gimbal studs 36, it is seen that the input shaft 54 will be able to rotate with the drive unit 14.

On the input shaft 54 there is a gear pulley 76 which is keyed by key 78 to the shaft 54.

In the lower housing 46 it is seen that there is a recess 80 and drilled passageways 82. In the passageways 82 are ball bearing races 84 and two ball bearing races 86. The ball bearing races 86 are separated by a spacer 88. Positioned in the ball bearing races 84 and 86 is a propeller shaft 90. In back of the ball bearing race 84 is a retainer ring 92 and in the ball bearing races 86 and on the shaft are retainer rings 94. Near the propeller end of the lower housing 46 and on the shaft 90 is a seal retainer 96. On the outer part of the seal retainer 96 is a retainer ring 98, a prop shaft seal 100 and surrounding the seal retainer 96 is an O-ring 102. On the propeller shaft 90 there is a gear pulley 104. The gear pulley 104 is keyed by key 106 to the shaft 90. A gear belt 108 runs around the gear pulley 76 on the input shaft 54 and the gear pulley 104 on the propeller shaft 90. The gear belt 108 may comprise a belt having a at steel core and a at tooth or flat teeth 110.

On the propeller shaft 90 there is mounted a propeller 112. A propeller shear pin 114 joins propeller 112 to the propeller shaft 90. On the end of the propeller shaft 90 there is a propeller spinner 116 which is joined to the propeller shaft 90 by means of a Cotter pin 118.

On the trailing end of the drive unit 14 there is an outwardly directed trim n housing 120 having on its lower end a trim lin 122. The trim iin 122 may be attached to the trim iin housing 120 by means of a screw or bolt 124.

In the transom 16 there is an opening or passageway 126. A support screw 128 having a rounded head 130 is in this passageway 126. In the forward part of the depending casing 44, i.e., that part facing the transom, there is a socket 132. The rounded head 130 ts in the socket 132. It is seen that the screw 128 is screwed into the capped passageway 26. On the inside of the transom 16 there is a nut 134 on the screw 128 and a washer 136 bearing against the transom 16. In this manner the lower part of the transom housing 12 is iirmly positioned and also the screw 128 is projected rearwardly of the transom 16. By adjusting the position of the screw and the rounded head or ball 130 the position of the drive unit 14 may be adjusted to improve the boats trim for best performance. Further, in the event that the drive unit 14 strikes an obstruction, the drive unit 14 can pivot about the horizontal gimbal studs 36 so as to give with the obstruction.

There are two desirable ways for turning the drive unit 14 around the gimbal studs 30. In FIGURE 3 there is illustrated one steering arrangement. In the transom 16 there is an opening or .a passageway 140. On the outside of the transom there is attached a socket 142. Positioned in the socket 142 is a ball 144 having a central passageway 146. Integral with the ball 144 and in the passageway 146 is positioned a tube 148. Inside of the tube 148 is a wire rope or wire cord 150. The wire rope 150 connects with a steering wheel or the like in the boat 152, see FIGURE 4. The wire rope connects with a steering rod 154. The steering rod 154 has a recess or cavity 156 and the wire rope 150 may be swaged and attached in this cavity 156. The end of the steering rod 154 projects outwardly at 158 and is threaded. The threaded end 158 is screwed into a socket member 160 having a threaded passageway 162. The socket member 160 has a socket which fits with a ball 164. The ball 164 is attached to the upper housing 42. As is readily appreciated with the movement of the steering rod 154 the drive unit 14 rotates around the vertical gimbal studs 30. In FIGURE 3 it is seen that there are two places for a ball member 164 on the upper housing 42. The drive unit 14 may be rotated by a steering rod 154 connecting with the ball 164 on either place 166 in the upper housing 42. Normally, the steering rod will be connected to that place in the housing near the passageway 140 in the transom 16. There may be a protective shield or tube 166 on the outer end of the steering rod 154.

In FIGURE 8 there is illustrated another steering arrangement for the drive unit 14. Briefly, this steering arrangement comprises an attachment to the steering ring or the gimbal ring 20. By rotating the steering ring or the gimbal ring 20 around the vertical gimbal studs 30 the drive unit 14 is rotated. It is seen that on the upper part of the gimbal ring 20 there is a flange 170. There is a steering rod 172 having a head 174. A pin 176 connects the head 174 with tiange 170 so that the flange 170 and the steering rod 172 may move with respect to each other. On the other end of the steering rod 172 there is a head 178. In the transom 16 there isa passageway 180. In the member 24 of the transom housing 12 there is a passageway 182. The steering rod 172 passes through the passageway 182 and also the passageway 180. The passageway 182 has an O-ring 184 which surrounds the steering rod 172. Attached to the transom 16, and on the inside of the boat, is a flange 186. A lever arm 188 is pinned to the ange 186 by pin 190. In the lever arm 188 there is a longitudinal slot 192. A pin 194 connects the head 178 to the steering rod 172 and the slot 192 of the lever arm 188. It is seen that the pin 194 is free to move in the slot 192. The lever arm 188 is connected to a tiller assembly 196 by the pin 190. With rotation of the tiller assembly 196 it is seen that the lever arm 188 also rotates. The tiller assembly 196 is connected to a steering cable 198 by means of a pin 200. The steering cable 198 may be connected with the steering wheel in the boat. From this it is seen that there is an alternative steering arrangement and which alternative makes it relatively easy to steer the drive unit 14 by rotating the gimbal ring 20.

In FIGURES 6 and 7 there is illustrated an alternative means for connecting the input shaft 54 with the propeller shaft 90. More particularly, on the input shaft 54 there is a gear or sprocket 202 and on the propeller shaft 90 there is Ia gear or sprocket 204. A silent chain 206 runs around the gear 202 and the gear 204 so as to have the `sprocket 202 in driving relationship with the sprocket 204.

In the boat 152, see FIGURE 4, there is an engine 210 which is mounted on supports 212. Attached to the output side of the engine 210 is a gear box 214. The gear box 214 has an output shaft 216 which connects with the universal joint 218. The universal join 218 connects with the transom shaft 64. As is seen in FIGURE 1 the transom shaft 64 connects with the universal joint 62 which in turn connects with the input shaft 54 of the drive unit.

From the preceding it is seen that I have provided a stern drive unit which makes it possible to utilize the inboard or marine engine already in a boat. Or, to install an inboard engine in a boat but to eliminate the cost and time of aligning the propeller shaft with the output shaft of the marine engine and the gear box. Such alignment is expensive as it requires considerable time to properly align the propeller shaft with the gear box. Further, I have accomplished this by means of .a stern drive unit which uses a flexible connecting means, viz, the gear belt 108 or the silent chain 206, to connect the input shaft of the drive unit 14 with the propeller shaft. Such flexibility elinminates many of the problems normally encountered in the alignment of the propeller shaft with the output of the gear box and engine arrangement in a boat.

Having presented my invention, what I claim is:

1. In an inboard-outboard drive for a boat having a transom provided with rst, second and third apertures, said third aperture being disposed below and in vertical alignment with said lirst `aperture and said rst and third apertures being spaced horizontally from said second aperture; a housing mounted on said transom and having a through opening aligned with said rst aperture; a drive unit disposed outboard of said boat, said unit including an input shaft mounted adjacent an upper part of said drive unit, a propeller' shaft mounted adjacent a lower part of said drive unit and drive chain means to transfer driving power from said input shaft to said propeller shaft; means connecting said drive unit adjacent the upper part thereof to said housing to permit relative movement therebetween; a source of power for said drive unit mounted within said boat; a drive means passing from said source of power through said iirst aperture and housing opening; means to drivingly connect the outboard end of said drive means to said drive unit input shaft and permit relative movement therebetween; steering means to pivot said drive unit horizontally with respect to said housing, said steering means being operable from within said boat and projecting outwardly through said second aperture; means connecting the outboard end 0f said steering means to said drive unit; tilt control means to pivot said drive unit vertically with respect to said housing, said tilt control means being operable from within said boat and including an adjustable screw shaft projecting through said third aperture; and last means for operably connecting the outboard end of said screw shaft to said drive unit, said last means including a ball member carried on the outboard end of said screw shaft and a ball receiving socket disposed on said drive unit intermediate the upper and lower parts thereof, said last means permitting operably connected relative movement between said screw shaft and said drive unit when said drive unit is pivoted horizontally by said steering means fand permitting said drive unit to be operably disconnected from said screw shaft upon independent vertical pivoting movement thereof away from said screw shaft.

References Cited UNITED STATES PATENTS 2,927,552 3/1960 Mickey 11S-41 2,809,605 10/1957 Russell 115-41 2,930,342 3/1960 Wanzer 115-35 X 3,088,430 5/ 1963 Champney 11S-41 3,136,287 6/1964 North 115-35 X 3,191,573 6/ 1965 Hixon 115-41 MILTON BUCHLER, Primary Examiner.

T. MAI OR, Assistant Examiner. 

